JP6531746B2 - Toner for developing electrostatic latent image - Google Patents

Description

  The present invention relates to a toner for electrostatic latent image development.

  There is known a toner including a plurality of toner particles including toner base particles and an external additive attached to the surface of the toner base particles (see, for example, Patent Document 1). In such a toner, the external additive functions as a spacer for the toner particles, so that the fluidity of the toner particles can be improved. If a low-resistance material is used as the external additive, the charging stability of the toner and the conductivity of the toner can be improved. If a material having high thermal conductivity is used as the external additive, the low temperature fixability of the toner can be improved.

JP-A-4-3171

  When forming an image on printing paper using toner, the fixing device of the image forming apparatus fixes the toner image transferred onto the printing paper onto the printing paper. Specifically, the fixing device heats and presses the toner image transferred to the printing paper. When the toner image is heated, the toner particles contained in the toner image are softened. The softened toner particles are pressed by the fixing device on the printing paper and fixed to the printing paper. Thus, the toner image transferred to the printing paper is fixed to the printing paper.

  As described above, at the time of fixing, the softened toner particles are pressed by the fixing device. Therefore, at the time of fixing, the softened toner particles contact the surface of the fixing device. Then, even after fixing, specifically, even after pressing by the fixing device, the adhesion state of the toner particles to the surface of the fixing device may be maintained. That is, high temperature offset may occur.

  It is considered that the occurrence of high temperature offset can be prevented if the toner particles are provided with an external additive. Specifically, if the toner particles are provided with an external additive, the external additive is sandwiched between the toner base particles and the surface of the fixing device at the time of fixing. Therefore, it is considered that the softened toner base particles can be prevented from coming into contact with the surface of the fixing device. Therefore, it is considered that the adhesion state of the toner base particles to the surface of the fixing device can be prevented from being maintained even after fixing.

  However, the external additive may be buried in the toner base particles by pressing by the fixing device, and the external additive may be separated from the surface of the toner base particles. When the external additive is buried in the toner base particles, or when the external additive is released from the surface of the toner base particles, the toner base particles contact the surface of the fixing device. Therefore, the adhesion state of the toner base particles to the surface of the fixing device may be maintained even after fixing. That is, even when the toner particles include the external additive, high temperature offset may occur.

  The present invention has been made in view of such circumstances, and its object is to improve the fluidity of toner particles, the charging stability of toner, the conductivity of toner, and the low temperature fixability of toner. It is another object of the present invention to provide an electrostatic latent image developing toner capable of preventing the occurrence of high temperature offset.

  The electrostatic latent image developing toner according to the present invention includes a plurality of toner particles. The toner particles include toner base particles and an external additive attached to the surface of the toner base particles. The external additive includes a plurality of first external additive particles containing diamond like carbon. The content of the first external additive particles in the toner particles is 1.00 to 3.00 parts by mass with respect to 100 parts by mass of the toner base particles. The number average primary particle diameter of the first external additive particles is 50 nm or more and 150 nm or less.

  According to the electrostatic latent image developing toner of the present invention, it is possible to prevent the occurrence of high temperature offset while improving the fluidity of the toner particles, the charging stability of the toner, the conductivity of the toner, and the low temperature fixability of the toner.

FIG. 3 is a view showing an example of the cross-sectional structure of toner particles contained in the electrostatic latent image developing toner according to the embodiment of the present invention.

  An embodiment of the present invention will be described. In the following, the evaluation results (values indicating the shape or physical properties, etc.) of the toner core, toner particles, toner base particles, or external additive are the number average of values measured for a considerable number of particles unless otherwise specified. It is.

Further, the number average particle diameter of the powder is not limited, and the number average value of the equivalent circle diameter of the primary particles (diameter of a circle having the same area as the projected area of the particles) measured using a microscope It is. If the measured value of the volume median diameter (D ₅₀ ) of the powder is not specified at all, the Coulter principle (pore electrical resistance method) is made using “Coulter Counter Multisizer 3” manufactured by Beckman Coulter, Inc. It is the value measured based on it.

  Moreover, each measured value of an acid value and a hydroxyl value is a value measured according to "JIS (Japanese Industrial Standard) K0070-1992", if it does not prescribe at all. Further, the glass transition point (Tg) is a value measured using a differential scanning calorimeter (“DSC-6220” manufactured by Seiko Instruments Inc.) unless otherwise specified. Further, the softening point (Tm) is a value measured using a Koka-type flow tester ("CFT-500D" manufactured by Shimadzu Corporation) unless otherwise specified.

  In addition, "system" may be added after the compound name to generically generically refer to the compound and its derivative. When a “system” is added after the compound name to represent a polymer name, it means that the repeating unit of the polymer is derived from the compound or its derivative. Moreover, acryl and methacryl may be generically called "(meth) acryl" generically.

  The electrostatic latent image developing toner according to the present embodiment (hereinafter sometimes referred to as toner) contains a plurality of toner particles. Such toners can be used, for example, in forming an image in an electrophotographic apparatus. Hereinafter, after describing an example of an image forming method using an electrophotographic apparatus, the configuration of the toner according to the present embodiment will be described.

[One Example of Image Forming Method by Electrophotographic Apparatus]
First, a charging device and an exposure device of an electrophotographic apparatus form an electrostatic latent image on the surface of a photosensitive drum based on image data. Next, the formed electrostatic latent image is developed using a developer containing toner.

  In the developing step, the developing sleeve of the developing roller disposed in the vicinity of the photosensitive drum attracts the carrier by the magnetic force of the magnet roll incorporated in the developing roller. At this time, toner is attracted to the surface of the carrier by electrostatic attraction due to triboelectric charging. Therefore, the toner is carried on the surface of the developing roller by attracting the carrier to the developing roller (more specifically, the developing sleeve of the developing roller). Then, the toner on the developing sleeve is supplied to the surface of the photosensitive drum by the rotation of the developing sleeve. As a result, toner adheres to the electrostatic latent image formed on the surface of the photosensitive drum, and a toner image is formed on the surface of the photosensitive drum.

  In the subsequent transfer step, after the toner image formed on the surface of the photosensitive drum is transferred to the intermediate transfer member, the toner image transferred to the intermediate transfer member is transferred to the printing paper. In the subsequent fixing process, a fixing device represented by a fixing roller heats and presses the toner. As a result, the toner particles (specifically, the binder resin) contained in the toner are softened, and the softened toner particles are pressed on the printing paper and fixed on the printing paper. Thus, an image is formed on the printing paper. After the image is formed, the cleaning member removes the toner remaining on the surface of the photosensitive drum.

[Configuration of electrostatic latent image developing toner according to the present embodiment]
The toner according to the present embodiment includes a plurality of toner particles. The toner particles comprise toner base particles and an external additive attached to the surface of the toner base particles. The external additive contains a plurality of first external additive particles containing diamond like carbon. The content of the first external additive particles in the toner particles is 1.00 parts by mass or more and 3.00 parts by mass or less with respect to 100 parts by mass of the toner base particles. The number average primary particle diameter of the first external additive particles is 50 nm or more and 150 nm or less.

  Here, the number average primary particle diameter of the first external additive particles is the circle equivalent diameter of the primary particles measured by observing the cross section of the toner particles using a microscope (for example, a transmission electron microscope). It is a number average value.

  The content of the first external additive particles in the toner particles can be determined by fluorescent X-ray analysis.

  The toner according to the exemplary embodiment includes a plurality of toner particles having the above configuration. As a result, it is possible to prevent the occurrence of high temperature offset while improving the fluidity of the toner particles, the charging stability of the toner, the conductivity of the toner, and the low temperature fixability of the toner. The following will be described in order.

In the toner according to the exemplary embodiment, the external additive includes a plurality of first external additive particles containing diamond like carbon (hereinafter sometimes referred to as DLC). Generally, in DLC, carbon having sp ³ bonds corresponding to a diamond structure and carbon having an sp ² structure corresponding to a graphite structure are irregularly mixed. Thus, DLC has both the properties of diamond and the properties of graphite. Therefore, DLC has low frictional resistance, low electrical resistance, and high thermal conductivity. Therefore, in the toner according to the exemplary embodiment, the flowability of the toner particles, the charging stability of the toner, the conductivity of the toner, and the low-temperature fixability of the toner can be improved.

  Specifically, since the frictional resistance of DLC is low, the slidability of the first external additive particles containing DLC can be enhanced. Here, in the toner according to the exemplary embodiment, the first external additive particle is included in the toner particle as an external additive, and thus functions as a spacer of the toner particle. Therefore, if the slidability of the first external additive particles can be enhanced, the fluidity of the toner particles can be enhanced.

  Since the electrical resistance of DLC is low, the electrical resistance of the first external additive particles containing DLC can be lowered. In the embodiment, the content of the first external additive particles in the toner particles is 1.00 parts by mass to 3.00 parts by mass with respect to 100 parts by mass of the toner base particles. From these facts, the electrical resistance of the toner particles can be maintained within an appropriate range.

  If the electrical resistance of the toner particles can be maintained in an appropriate range, the charge amount of the toner can be maintained in an appropriate range. Thus, the charging stability of the toner can be enhanced. The toner having excellent charge stability includes characteristics that the charge amount distribution of the toner is sharp, characteristics that can maintain the charge amount of the toner at a desired charge amount when an image is formed using the toner, and the toner is used. The term "toner" means a toner having the property of being able to maintain the charge amount of the toner at a desired charge amount when an image is continuously formed.

  If the charging stability of the toner can be enhanced, the developability of the toner is enhanced. For example, an image excellent in image density can be formed. Further, if the charging stability of the toner can be enhanced, it is possible to prevent the scattering of the charging failure toner, so that the occurrence of fogging can be prevented.

  If the electrical resistance of the toner particles can be maintained within an appropriate range, the conductivity of the toner can also be maintained within an appropriate range. Therefore, generation of a black dot image can be prevented. In the following, after explaining the reason why the black dot image is generated, the reason why the generation of the black dot image can be prevented in the present embodiment will be described.

  After the image formation, the cleaning member removes the toner remaining on the surface of the photosensitive drum. When a cleaning blade is used as the cleaning member, the edge portion of the cleaning blade removes the toner remaining on the surface of the photosensitive drum. However, the toner removed from the surface of the photosensitive drum may stay at the edge portion of the cleaning blade. When the staying toner is present at the edge portion of the cleaning blade, the staying toner is rubbed against the surface of the photosensitive drum by the rotation of the photosensitive drum. This causes an increase in the charge amount of the staying toner. When the charge amount of the staying toner is excessively increased, the electrical breakdown of the photosensitive drum is likely to occur. As a result, in the obtained image, a black dot image is formed at an interval substantially equal to the diameter of the photosensitive drum (generation of a black dot image).

  However, in the toner according to the exemplary embodiment, the electrical resistance of the toner particles can be maintained within an appropriate range. Therefore, even when the staying toner is present at the edge portion of the cleaning blade, it is possible to prevent the charging amount of the staying toner from excessively increasing. Therefore, since the electrical breakdown of the photosensitive drum can be prevented, the generation of the black dot image can be prevented.

  It is considered that generation of a black dot image can be prevented also by the number average primary particle diameter of the first external additive particles being 50 nm or more. More specifically, as described later, if the number average primary particle diameter of the first external additive particles is 50 nm or more, the first external additive particles are the toner matrix even when pressure is applied to the toner particles. It can be prevented from being buried in particles. Therefore, even when pressure is applied to the staying toner by rubbing the staying toner on the surface of the photosensitive drum, the first external additive particles can be prevented from being buried in the toner base particles in the staying toner. Also by this, it is possible to prevent the charge amount of the staying toner from excessively increasing. Therefore, the electrical breakdown of the photosensitive drum can be prevented, and hence the generation of the black dot image can be prevented.

  Since the thermal conductivity of DLC is high, the thermal conductivity of the first external additive particle containing DLC can be enhanced. Here, in the toner according to the exemplary embodiment, the first external additive particles are included in the toner particles as an external additive. Therefore, if the thermal conductivity of the first external additive particles can be enhanced, the thermal conductivity of the toner particles can be enhanced. Thus, the low temperature fixability of the toner can be enhanced.

  In the toner according to the exemplary embodiment, the number average primary particle diameter of the first external additive particles containing DLC is 50 nm or more and 150 nm or less, and the content of the first external additive particles in the toner particles is 100 mass The amount is 1.00 parts by mass or more based on the toner base particles of the part. This can prevent the occurrence of high temperature offset.

  Specifically, the first external additive particles contain DLC. Here, DLC is more heat resistant than a resin component (specifically, a binder resin) contained in toner base particles, and is not softened, melted or decomposed at the softening point of the resin component contained in toner base particles. Therefore, at the time of fixing, even if the resin component contained in the toner base particles is softened, the first external additive particles containing DLC are not softened, melted and decomposed. That is, at the time of fixing, the resin component contained in the toner base particles is softened preferentially.

  Here, the number average primary particle diameter of the first external additive particles is 50 nm or more and 150 nm or less. If the number average primary particle diameter of the first external additive particles is 50 nm or more, the first external additive particles are buried in the toner base particles even when the toner particles are pressed by the fixing device on the printing paper Can be prevented. This effect is easily obtained when the content of the first external additive particles in the toner particles is 1.00 parts by mass or more with respect to 100 parts by mass of the toner base particles. In addition, when the number average primary particle diameter of the first external additive particles is 150 nm or less, the size of the first external additive particles can be sufficiently smaller than the size of the toner base particles. Therefore, even when the toner particles are pressed by the fixing device on the printing paper, it is possible to prevent the first external additive particles from being detached from the surface of the toner base particles. This effect is also easily obtained when the content of the first external additive particles in the toner particles is 1.00 parts by mass or more with respect to 100 parts by mass of the toner base particles. From these facts, the number average primary particle diameter of the first external additive particles is 50 nm or more and 150 nm or less, and the content of the first external additive particles in the toner particles is 1 per 100 mass parts toner base particle. If it is .00 parts by mass or more, at the time of fixing, the first external additive particles can be sandwiched between the toner base particles and the surface of the fixing device. Therefore, at the time of fixing, it is possible to prevent excessive contact of the softened toner base particles with the surface of the fixing device.

  As described above, at the time of fixing, the toner particles can be fixed to the printing paper without excessive contact of the component softened by heating (specifically, the binder resin) with the surface of the fixing device. Therefore, it is possible to prevent the component softened by heating from adhering to the surface of the fixing device even after fixing. That is, the occurrence of high temperature offset can be prevented.

Preferably, the Raman spectrum of the first external additive particle has the following first to fourth characteristics. As a result, the fluidity of the toner particles, the charging stability of the toner, the conductivity of the toner, and the low temperature fixability of the toner can be further improved, and the occurrence of high temperature offset can be further prevented.
First feature: in the Raman spectrum of the first external additive particle, a first band derived from a diamond structure and a second band derived from a graphite structure are present.
The second feature: In the first band, the Raman shift in wavenumber region is 1320 cm ^-1 or more 1360 cm ^-1 or less, scattering intensity is maximized.
The third feature: in the second band, the Raman shift in wavenumber region is 1520 cm ^-1 or more 1560 cm ^-1 or less, scattering intensity is maximized.
Fourth feature: the full width at half maximum of the first band is greater than the full width at half maximum of the second band.

  The Raman spectrum of the first external additive particle is measured using a commercially available Raman spectrum spectrophotometer (for example, "NRS-7000" manufactured by JASCO Corporation). As a measurement sample, it is preferable to use a powder composed of a plurality of first external additive particles.

  The obtained Raman spectrum is preferably analyzed according to the following method. The first band and the second band are each curve-fitted with a predetermined function (for example, a Gaussian function). Thereby, in each of the first band and the second band, it is possible to obtain the Raman shift value when the scattering intensity is maximum, the full width at half maximum, and the maximum value (described later) of the scattering intensity. The curve fitting is preferably performed using analysis software installed in the Raman spectrum spectrophotometer used to measure the Raman spectrum of the first external additive particle. In the fourth aspect, it is preferable that the full width at half maximum value of the first band is twice or more and three or less times as large as the full width at half maximum value of the second band.

  If the DLC contained in the first external additive particle is hydrogenated amorphous carbon (aC: H), the Raman spectrum shape of the first external additive particle tends to have the above first to fourth characteristics. . Therefore, the first external additive particles preferably contain hydrogenated amorphous carbon (aC: H) as DLC.

When the first external additive particle contains hydrogenated amorphous carbon (aC: H) as DLC, the shape of the Raman spectrum of the first external additive particle tends to have the following fifth feature.
Fifth feature: The maximum value of the scattering intensity in the first band (D band) is not less than 2 times and not more than 3 times the maximum value of the scattering intensity in the second band (G band).

  Preferably, the first external additive particle has a first core particle and a first coat layer formed on the surface of the first core particle. The first coat layer preferably contains DLC.

  When the first coat layer contains DLC, the DLC is present on the surface of the first external additive particle. As a result, the fluidity of the toner particles, the charging stability of the toner, the conductivity of the toner, and the low-temperature fixability of the toner can be improved, as compared with the case where the DLC is dispersed in the first external additive particles. It is possible to prevent the occurrence of high temperature offset.

The first core particle is preferably excellent in heat resistance, and is, for example, a silica particle or an alumina (Al ₂ O ₃ ) particle. The first core particle is preferably a silica particle, and more preferably a silica particle which has not been subjected to a hydrophobization treatment and a charging treatment. It is considered that silanol groups (—SiOH groups) are present on the surface of silica particles that have not been subjected to hydrophobization treatment and charging treatment. Here, OH contained in the silanol group has high reactivity. Therefore, when the first coat layer is formed on the surface of the silica particle which has not been subjected to the hydrophobization treatment and the electrification treatment, OH contained in the silanol group is easily substituted by the diamond structure or the graphite structure. Thereby, the first coat layer can be firmly formed on the surface of the first core particle. Therefore, it is possible to prevent the first coat layer from peeling off the surface of the first core particle, for example, during image formation. Therefore, it is possible to further prevent the occurrence of high temperature offset while further improving the fluidity of the toner particles, the charging stability of the toner, the conductivity of the toner, and the low temperature fixability of the toner.

  The first coat layer preferably comprises only DLC, but may further contain an adhesive for adhering DLC to the surface of the first core particle. In consideration of the fact that the number average primary particle diameter of the first external additive particles is 50 nm or more and 150 nm or less, the thickness of the first coating layer is preferably 5 nm or more and 10 nm or less. The thickness of the first coat layer is measured according to the method described in the examples below.

  Preferably, the external additive contains a plurality of second external additive particles that do not contain DLC but contain silica, but does not contain external additive particles that contain titanium oxide. Generally, toner particles contain both silica particles and titanium oxide particles as an external additive. This is because the silica particles and the titanium oxide particles have different functions as external additives. However, it is considered that the function of the titanium oxide particles as the external additive is included in the function of the first external additive particle as the external additive. Therefore, when the toner particles contain the first external additive particle as the external additive, the titanium oxide particles may not be used as the external additive.

More preferably, the second external additive particles are silica particles that have been subjected to hydrophobization treatment and charging treatment. Here, the hydrophobized silica particle means that at least one of the silanol groups present on the surface of the silica particle has OH substituted with a functional group that is less reactive than OH. . Examples of functional groups less reactive than OH include, for example, alkyl groups. The silica particles subjected to the charging treatment include silica particles subjected to the positive charging treatment and silica particles subjected to the negative charging treatment. The silica particles subjected to the positive charging treatment mean that OH is substituted with a functional group having a higher positive charge than OH in at least one of the silanol groups present on the surface of the silica particles. Examples of the functional group having higher positive chargeability than OH include, for example, an amino group (—NH ₂ group). The negatively charged silica particles mean that at least one of the silanol groups present on the surface of the silica particles has OH substituted with a more negatively charged functional group than OH. The functional group having higher negative chargeability than OH includes, for example, a functional group containing a fluorine atom, and more specifically, an alkyl group in which at least one hydrogen atom is substituted by a fluorine atom. Adjusting the content of the second external additive particles in the toner particles such that the content of the external additive in the toner particles is 1.0 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the toner base particles Is preferred.

  Hereinafter, with reference to FIG. 1, an example of the configuration of toner particles contained in the toner according to the exemplary embodiment will be described. FIG. 1 is a view showing an example of the cross-sectional structure of toner particles.

  The toner particles 10 shown in FIG. 1 include toner base particles 20 and an external additive. The external additive includes a plurality of first external additive particles 30 and a plurality of second external additive particles 40. The first external additive particles 30 each have a first core particle 31 and a first coat layer 33. The first core particle 31 is a silica particle which has not been subjected to hydrophobization treatment and charging treatment. The first coat layer 33 is formed on the surface of the first core particle 31 and contains only DLC. The second external additive particles 40 are silica particles that have been subjected to a hydrophobization treatment and a positive charging treatment, respectively. The example of the configuration of the toner particles contained in the toner according to the exemplary embodiment has been described above with reference to FIG.

  The configuration of the toner according to the present embodiment and an example of the configuration of the toner particles contained in the toner according to the present embodiment have been described above. The toner particles contained in the toner according to the exemplary embodiment may include capsule toner as toner base particles, or non-capsule toner as toner base particles. The capsule toner has a toner core and a shell layer formed on the surface of the toner core. Non-capsulated toner has a toner core but no shell layer. Therefore, in non-capsulated toner, the toner core corresponds to toner base particles.

[Method of producing electrostatic latent image developing toner according to the present embodiment]
It is preferable that the method of manufacturing the toner according to the exemplary embodiment includes a process of manufacturing toner base particles, a process of manufacturing an external additive, and an external addition process.

<Production process of toner base particles>
When producing non-capsulated toner as toner base particles, it is preferable to produce toner base particles by a known aggregation method or a known grinding method.

  When producing capsule toner as toner mother particles, it is preferable to produce capsule toner according to the following method. First, a toner core is manufactured by a known aggregation method or a known grinding method. Next, a shell layer is formed on the surface of the toner core by, for example, in-situ polymerization method, in-liquid curing coating method, or coacervation method. Thus, a capsule toner can be manufactured.

<Production process of external additive>
The manufacturing process of the external additive includes a manufacturing process of the first external additive particle, and preferably further includes a manufacturing process of the second external additive particle.

(Step of producing first external additive particles)
The step of producing the first external additive particles preferably includes the step of producing the first core particle and the step of forming the first coat layer.

(Step of producing first external additive particle: step of producing first core particle)
In the production process of the first core particle, it is preferable to produce silica particles which have not been subjected to the hydrophobization treatment and the electrification treatment. The silica particles which have not been subjected to the hydrophobization treatment and the electrification treatment are preferably produced by a known sol-gel method.

(Step of producing first external additive particle: step of forming first coat layer)
The method for forming the first coat layer on the surface of the first core particle is not particularly limited. Preferably, a plasmatized source gas is caused to act on the flowing first core particle using an electron beam excited plasma. Thereby, it is easy to manufacture the first external additive particles having the above first to fourth characteristics in the Raman spectrum shape. In addition, since the first coat layer can be easily formed on the surface of the first core particle which is a sphere, the first external additive particle can be easily manufactured. Furthermore, since the first coat layer can be simultaneously formed on the plurality of first core particles, the plurality of first external additive particles can be simultaneously manufactured.

  As a method of generating an electron beam excited plasma, for example, the following method may be mentioned. The electrons output from the electron beam gun are accelerated, and the accelerated electrons are irradiated to the rare gas. As a result, the rare gas is dissociated, ionized or excited to generate an electron beam excited plasma.

  In the present embodiment, a first coat layer containing DLC is formed. Therefore, it is preferable to use a gas containing a hydrocarbon gas as the source gas. As a gas containing hydrocarbon gas, for example, methane gas or a mixed gas of methane gas and hydrogen gas can be used.

  The time for causing the source gas converted into plasma to act on the first core particle, the discharge current supplied to the electron beam gun, the acceleration voltage applied to the electrons output from the electron beam gun, the bias voltage applied to the first core particle The thickness of the first coat layer can be adjusted by adjusting at least one of the above.

(Production process of second external additive particles)
In the production process of the second external additive particles, it is preferable to produce silica particles that have been subjected to hydrophobization treatment and charging treatment. For example, it is preferable to produce silica particles by a known sol-gel method and to subject the produced silica particles to a hydrophobization treatment and a positive charging treatment or a negative charging treatment.

  In the hydrophobization treatment, it is preferable to treat the surface of the silica particles using a known hydrophobizing agent. In the positive charging treatment, it is preferable to treat the surface of the silica particles using a known positive charge imparting agent. In the negative charge treatment, it is preferable to treat the surface of the silica particles using a known negative charge imparting agent.

<External addition process>
In the external addition step, an external additive is attached to the surface of the toner base particles. Preferably, the toner base particles and the external additive are mixed using a mixer (for example, an FM mixer manufactured by Nippon Coke Industry Co., Ltd.). Thus, the external additive is physically bonded to the surface of the toner base particles. Thus, a toner containing a large number of toner particles is obtained.

[Example of material of toner mother particles]
Hereinafter, specific examples of the material of the toner base particles will be described. When toner base particles are non-capsule toner, the toner base particles correspond to the following toner core. When the toner base particle is a capsule toner, the toner base particle comprises the following toner core and the following shell layer.

(Toner core)
The toner core contains a binder resin. The toner core may further contain at least one of a colorant, a release agent, a charge control agent, and a magnetic powder.

(Toner core: Binder resin)
In the toner core, generally, the binder resin occupies most (for example, 85% by mass or more) of the components. Therefore, it is considered that the properties of the binder resin greatly affect the properties of the entire toner core.

  Further, by combining and using a plurality of resins as the binder resin, the properties of the binder resin (specifically, the hydroxyl value, the acid value, the glass transition point, or the softening point) can be adjusted. For example, when the binder resin has an ester group, a hydroxyl group, an ether group, an acid group, or a methyl group, the toner core tends to be anionic. When the binder resin has an amino group or an amide group, the toner core tends to be cationic. In order for the binder resin to have strong anionic property, it is preferable that at least one of the acid value and the hydroxyl value of the binder resin is 10 mg KOH / g or more.

  The toner core preferably contains a thermoplastic resin. As a thermoplastic resin, a polyester resin, a styrene resin, acrylic acid resin, an olefin resin, a vinyl resin, a polyamide resin, or a urethane resin can be used suitably, for example. Further, a copolymer of each of these resins, that is, a copolymer in which an arbitrary repeating unit is introduced into the above-mentioned resin can also be suitably used as a thermoplastic resin constituting toner particles. For example, a styrene-acrylic acid resin or a styrene-butadiene resin can also be suitably used as a thermoplastic resin constituting a toner core.

  The polyester resin is obtained by condensation polymerization of one or more alcohols and one or more carboxylic acids. As an alcohol for synthesizing a polyester resin, for example, a dihydric alcohol or a trivalent or higher alcohol shown below can be suitably used. As the dihydric alcohol, for example, diols or bisphenols can be used. As a carboxylic acid for synthesize | combining polyester resin, the bivalent carboxylic acid or trivalent or more carboxylic acid shown below can be used conveniently, for example.

  Preferred examples of the diols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 2-butene-1,4 Diol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol or polytetramethylene glycol.

  Preferable examples of bisphenols include bisphenol A, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, or bisphenol A propylene oxide adduct.

  Preferred examples of trihydric or higher alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, and 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane or 1,3,5- Trihydroxymethylbenzene is mentioned.

  Preferred examples of the divalent carboxylic acid include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, malonic acid , Succinic acid, alkylsuccinic acid (more specifically, n-butylsuccinic acid, isobutylsuccinic acid, n-octylsuccinic acid, n-dodecylsuccinic acid, or isododecylsuccinic acid, etc.), or alkenylsuccinic acid (more specifically Examples thereof include n-butenylsuccinic acid, isobutenylsuccinic acid, n-octenylsuccinic acid, n-dodecenylsuccinic acid, and isododecenylsuccinic acid).

  Preferred examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylene carboxyl) Methane, 1,2,7,8-octane tetracarboxylic acid, pyromellitic acid, or Empol trimer acid can be mentioned.

  The styrene-acrylic acid resin is a copolymer of one or more styrene monomers and one or more acrylic monomers. In order to synthesize a styrene-acrylic acid-based resin, for example, styrene-based monomers and acrylic acid-based monomers shown below can be suitably used. By using an acrylic acid type monomer, a carboxyl group can be introduced into a styrene-acrylic acid type resin. Moreover, a hydroxyl group can be introduce | transduced into styrene- acrylic acid type resin by using the monomer which has a hydroxyl group. As the monomer having a hydroxyl group, for example, p-hydroxystyrene, m-hydroxystyrene, or (meth) acrylic acid hydroxyalkyl ester can be used.

  Preferred examples of styrenic monomers include styrene, alkylstyrene, p-hydroxystyrene, m-hydroxystyrene, vinyl toluene, α-chlorostyrene, o-chlorostyrene, m-chlorostyrene or p-chlorostyrene Be Examples of the alkylstyrene include α-methylstyrene, p-ethylstyrene, and 4-tert-butylstyrene.

  Preferred examples of the acrylic acid-based monomer include (meth) acrylic acid, (meth) acrylic acid alkyl ester, or (meth) acrylic acid hydroxyalkyl ester. Preferred examples of (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, (meth) acrylic Examples include n-butyl acid, iso-butyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate. Preferred examples of (meth) acrylic acid hydroxyalkyl ester include 2-hydroxyethyl (meth) acrylic acid, 3-hydroxypropyl (meth) acrylic acid, 2-hydroxypropyl (meth) acrylic acid, or (meth) acrylic The acid 4-hydroxybutyl is mentioned.

  As acrylic resin, acrylic acid ester polymer or methacrylic acid ester polymer can be used, for example. As an olefin resin, a polyethylene resin or a polypropylene resin can be used, for example. As a vinyl resin, a vinyl chloride resin, polyvinyl alcohol, vinyl ether resin, or N-vinyl resin can be used, for example.

(Toner Core: Colorant)
As the colorant, known pigments or dyes may be used in accordance with the color of the toner. In order to form a high-quality image using toner, the amount of the colorant is preferably 1.00 to 20.0 parts by mass with respect to 100 parts by mass of the binder resin.

  The toner core may contain a black colorant. Examples of black colorants include carbon black. The black colorant may be a colorant toned to black using a yellow colorant, a magenta colorant, and a cyan colorant.

  The toner core may contain color colorants such as yellow colorants, magenta colorants, or cyan colorants.

  As the yellow colorant, for example, one or more compounds selected from the group consisting of condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and arylamide compounds can be used. Examples of yellow colorants include C.I. I. Pigment yellow (3, 12, 13, 14, 15, 17, 62, 74, 83, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155 168, 174, 175, 176, 180, 181, 191 or 194), Naphthol Yellow S, Hansa Yellow G or C.I. I. Bat yellow can be suitably used.

  The magenta colorant is selected, for example, from the group consisting of condensation azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. One or more compounds can be used. Examples of magenta colorants include C.I. I. Pigment red (2, 3, 5, 6, 7, 19, 19, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177 184, 185, 202, 206, 220, 221 or 254) can be suitably used.

  As the cyan colorant, for example, one or more compounds selected from the group consisting of a copper phthalocyanine compound, an anthraquinone compound, and a basic dye lake compound can be used. Examples of cyan colorants include C.I. I. Pigment blue (1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62 or 66), phthalocyanine blue, C.I. I. Bat blue or C.I. I. Acid blue can be suitably used.

(Toner core: mold release agent)
The release agent is used, for example, for the purpose of improving the fixing property or the offset resistance of the toner. In order to enhance the anionic property of the toner core, it is preferable to produce the toner core using an anionic wax. In order to improve the fixing property or the offset resistance of the toner, the amount of the releasing agent is preferably 1.00 to 30.0 parts by mass with respect to 100 parts by mass of the binder resin.

  As a mold release agent, for example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, or aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxidized polyethylene wax or block thereof Oxides of aliphatic hydrocarbon waxes such as copolymers; vegetable waxes such as candelilla wax, carnauba wax, wax wax, jojoba wax, or rice wax; animal nature such as bees wax, lanolin or wax wax Waxes; mineral waxes such as ozokerite, ceresin, or petrolatum; waxes based on fatty acid esters such as montanic acid ester wax or castor wax; fatty acids such as deacidified carnauba wax The wax portion of the ester or the whole was deoxygenated can be suitably used. One type of release agent may be used alone, or two or more types of release agents may be used in combination.

  A compatibilizer may be added to the toner core in order to improve the compatibility between the binder resin and the release agent.

(Toner core: charge control agent)
The charge control agent is used, for example, for the purpose of improving the charge stability or charge rise characteristics of the toner. The charge rising characteristic of the toner is an indicator of whether or not the toner can be charged to a predetermined charge level in a short time.

  By including a negatively chargeable charge control agent in the toner core, the anionic property of the toner core can be enhanced. In addition, the cationic property of the toner core can be enhanced by containing a positively chargeable charge control agent in the toner core. However, in the case where sufficient chargeability is ensured in the toner, it is not necessary to contain the charge control agent in the toner core.

(Toner core: Magnetic powder)
As the material of the magnetic powder, for example, a ferromagnetic metal or an alloy thereof, a ferromagnetic metal oxide, or a material subjected to a ferromagnetic treatment can be suitably used. As a ferromagnetic metal, iron, cobalt or nickel can be used, for example. As the ferromagnetic metal oxide, for example, ferrite, magnetite or chromium dioxide can be used. As a ferromagnetization process, a heat treatment is mentioned, for example. One type of magnetic powder may be used alone, or two or more types of magnetic powder may be used in combination.

  In order to suppress the elution of metal ions (for example, iron ions) from the magnetic powder, it is preferable to surface-treat the magnetic powder. In the case where a shell layer is formed on the surface of the toner core under acidic conditions, when metal ions are eluted on the surface of the toner core, the toner cores are easily fixed to each other. By suppressing the elution of metal ions from the magnetic powder, it is considered that the adhesion between toner cores can be suppressed.

(Shell layer)
The shell layer preferably contains a thermoplastic resin. As a thermoplastic resin which a shell layer contains, the thermoplastic resin as described in said (toner core: binder resin) can be used, for example. Preferably, the shell layer contains a copolymer of one or more styrenic monomers and one or more acrylic acid monomers. Thereby, the charging stability of the toner can be further improved. For example, styrene can be used as the styrene-based monomer. As an acrylic acid type monomer, acrylic acid ester can be used, for example.

  The shell layer may further contain a thermosetting resin. As a suitable example of the thermosetting resin which a shell layer contains, amino aldehyde resin, a polyimide resin, or a xylene resin is mentioned. An aminoaldehyde resin is a resin produced by condensation polymerization of a compound having an amino group and an aldehyde. Here, for example, formaldehyde can be used as the aldehyde. Examples of the aminoaldehyde resin include melamine resins, urea resins, sulfonamide resins, glyoxal resins, guanamine resins, or aniline resins. As the polyimide resin, for example, a maleimide polymer or a bismaleimide polymer can be used.

[Example of application of toner according to this embodiment]
The toner according to the present embodiment can be suitably used, for example, as a positively chargeable toner for developing an electrostatic latent image. The toner of the present embodiment may be used as a one-component developer or may be used as a toner contained in a two-component developer.

(2-component developer)
When the toner of the present embodiment is used as a toner contained in a two-component developer, a two-component developer can be prepared by mixing the toner and a carrier using a mixing device. As a mixing apparatus, for example, a ball mill can be used.

  It is preferable to use a ferrite carrier as the carrier. Thereby, a high quality image can be formed. As the carrier, it is more preferable to use magnetic carrier particles comprising a carrier core and a resin layer covering the carrier core. This makes it possible to form a high quality image over a long period of time. In order to impart magnetism to the carrier particles, the carrier particles may be formed of a magnetic material, or the carrier particles may be formed of a resin in which the magnetic particles are dispersed. In addition, magnetic particles may be dispersed in a resin layer that covers the carrier core. In order to form a high-quality image, the amount of toner in the two-component developer is preferably 5.00 parts by mass or more and 15.0 parts by mass or less with respect to 100 parts by mass of the carrier. The positively chargeable toner contained in the two-component developer is positively charged by the friction with the carrier.

In the example, toners T-1 to T-12 were manufactured, and the manufactured toners T-1 to T-12 were evaluated. Table 1 describes the physical properties of DLC / silica particles (silica particles whose surface is coated with a DLC film) E-1 to E-5. In Table 1, the particle size means the number average primary particle size of DLC / silica particles. The core diameter means the number average primary particle diameter of core particles (specifically, silica particles) contained in the DLC / silica particles. The δ ₁ , Δd ₁ , I ₁ , δ ₂ , Δd ₂ , and I ₂ are as described below. The D band is a band derived from a diamond structure. Also, the G band is a band derived from a graphite structure.
Raman shift when the scattering intensity is maximum in the δ ₁ : D band Δd ₁ : full width at half maximum of the D band I ₁ : maximum value of scattering intensity in the D band δ ₂ : maximum scattering intensity in the G band Raman shift Δd ₂ : full width at half maximum of G band I ₂ : maximum value of scattering intensity of G band

  Hereinafter, the method of manufacturing DLC / silica particles E-1 to E-5 and the method of measuring physical properties will be sequentially described, and then the method of manufacturing toner T-1 to T-12, an evaluation method, and evaluation results will be sequentially described. . In addition, in the evaluation which an error produces, the measurement value of a considerable number which an error becomes small enough was obtained, and the arithmetic mean of the obtained measurement value was made into the evaluation value. Further, the number average particle diameter of the powder is a number average value of equivalent circular diameters of primary particles measured using a transmission electron microscope (TEM), unless specified.

[Production of DLC / silica particles]
(Production of DLC / Silica Particles E-1)
As core particles, silica particles (silica particles produced by a sol-gel method, manufactured by Shin-Etsu Chemical Co., Ltd., number average primary particle diameter: 45 nm) were prepared. The prepared silica particles were silica particles which were not subjected to hydrophobization treatment and charging treatment.

  Next, a DLC film was formed on the surface of the silica particles using a film forming apparatus ("DLC-MR3" manufactured by Shimadzu Corporation) shown below. In the following, after briefly explaining the configuration of the used film forming apparatus, a method of forming a DLC film will be described.

  The film forming apparatus used includes a vacuum chamber as a film forming chamber. In the vacuum chamber, a barrel-type container for containing silica particles is rotatably provided. An electron beam gun is attached to the side of the vacuum chamber, and the electron beam from the electron beam gun passes through the vacuum chamber and enters the barrel container. An acceleration electrode for accelerating electrons (electrons contained in the electron beam) is provided on the side of the vacuum chamber opposite to the side on which the electron beam gun is attached. An electron beam gun has a filament and a discharge electrode. A discharge current is supplied between the filament and the discharge electrode, and an acceleration voltage is applied between the discharge electrode and the acceleration electrode.

  A DLC film was formed on the surface of the silica particles by the following method. First, 500 g of silica particles were placed in a barrel-type vessel, and then the vacuum chamber was evacuated. Next, argon gas was supplied to the discharge space of the electron beam gun (specifically, the space between the filament and the discharge electrode), and a direct current discharge of argon was caused in the discharge space triggered by thermal electrons emitted from the filament. . Further, methane gas was supplied to the vacuum chamber, and the pressure in the vacuum chamber was 6 mTorr. Subsequently, an accelerating voltage was applied to extract the electron beam from the discharge space of the electron beam gun into the vacuum chamber. As a result, an electron beam excited plasma is generated coaxially with the rotation axis of the barrel type container in the barrel type container. Thereafter, the discharge current was 10 A, the acceleration voltage was 60 V, the bias voltage to the barrel was -10 V, and the barrel was rotated for 60 minutes. Thus, while flowing the silica particles, methane gas converted to plasma was made to act on the silica particles using electron beam excitation plasma. As a result, DLC / silica particles E-1 were obtained. In the obtained DLC / silica particle E-1, the thickness of the DLC film was 5 nm.

(Production of DLC / Silica Particles E-2)
Except using silica particles (silica particles manufactured by the sol-gel method, number average primary particle diameter: 145 nm, manufactured by Shin-Etsu Chemical Co., Ltd.) as silica particles, according to the method of manufacturing DLC / silica particles E-1 , DLC / silica particles E-2 were produced. In the obtained DLC / silica particle E-2, the thickness of the DLC film was 5 nm.

(Production of DLC / Silica Particles E-3)
According to the method for producing DLC / silica particle E-1, except that silica particles (silica particles produced by the sol-gel method, number average primary particle diameter: 95 nm, manufactured by Shin-Etsu Chemical Co., Ltd.) are used as the silica particles , DLC / silica particles E-3 were produced. In the obtained DLC / silica particle E-3, the thickness of the DLC film was 5 nm.

(Production of DLC / Silica Particles E-4)
Except using silica particles (silica particles manufactured by the sol-gel method, number average primary particle diameter: 40 nm, manufactured by Shin-Etsu Chemical Co., Ltd., as the silica particles, according to the method of manufacturing DLC / silica particles E-1 , DLC / silica particles E-4 were produced. In the obtained DLC / silica particle E-4, the thickness of the DLC film was 5 nm.

(Production of DLC / Silica Particles E-5)
According to the method for producing DLC / silica particles E-1 except that silica particles (silica particles produced by the sol-gel method, number average primary particle diameter: 150 nm, manufactured by Shin-Etsu Chemical Co., Ltd.) are used as the silica particles , DLC / silica particles E-5 were produced. In the obtained DLC / silica particle E-5, the thickness of the DLC film was 5 nm.

[Measurement of physical properties of DLC / silica particles]
(Measurement of number average primary particle diameter of DLC / silica particles)
Regarding each of the DLC / silica particles E-1 to E-5 obtained as described above, the number average primary particle diameter of the DLC / silica particles was measured using a scanning electron microscope (SEM). The results are shown in Table 1.

  In each of the DLC / silica particles E-1 to E-5, the variation of the primary particle diameter in the plurality of DLC / silica particles was small. Specifically, the powder composed of a plurality of DLC / silica particles E-1 has a particle diameter of [number-average primary particle diameter (that is, particle diameter shown in Table 1) ± 1 nm determined according to the above-mentioned method] DLC / silica particles having (equivalent circle diameter) were contained at a rate of 85% by number or more. Powder composed of a plurality of DLC / silica particles E-2, powder composed of a plurality of DLC / silica particles E-3, powder composed of a plurality of DLC / silica particles E-4, and a plurality The same applies to the powder composed of DLC / silica particle E-5.

(Measurement of DLC film thickness)
The thickness of the DLC film was measured for each of the DLC / silica particles E-1 to E-5 obtained as described above. As an object to be measured, DLC / silica particles E-1 to E-5 were used. First, a cross-sectional TEM photograph of DLC / silica particles was taken using a transmission electron microscope (TEM, “H-7100 FA” manufactured by Hitachi High-Technologies Corporation). Next, cross-sectional TEM photographs of the obtained DLC / silica particles were analyzed using image analysis software ("WinROOF" manufactured by Mitani Corporation).

  Specifically, first, two straight lines perpendicular to each other at the approximate center of the cross section of the DLC / silica particle were drawn. In each of the two straight lines, the length from the interface between the silica particles and the DLC film (corresponding to the surface of the silica particles) to the surface of the DLC film was measured. The average value of the four lengths measured in this manner was taken as the thickness of the DLC film provided in one DLC / silica particle. The measurement of the thickness of such a DLC film was performed on a plurality of DLC / silica particles, and the average value of the thickness of the DLC film included in the plurality of DLC / silica particles was determined. The average value of the thickness of the DLC film determined in this manner is taken as the "thickness of the DLC film".

  When the boundary between the silica particle and the DLC film is unclear in the cross-sectional TEM photograph of the toner base particle, the cross-sectional TEM photograph of the DLC / silica particle is used as an electron energy loss spectroscopy (EELS) detector (manufactured by Gatan Co., Ltd.) It analyzed using GIF TRIDIEM (trademark) and image analysis software ("WinROOF" by Mitani Corporation). Thereby, the boundary between the silica particle and the DLC film became clear in the cross-sectional TEM photograph of the DLC / silica particle.

(Measurement of Raman spectrum of DLC / silica particle)
A Raman spectrum was measured for each of the obtained DLC / silica particles E-1 to E-5. As an object to be measured, DLC / silica particles E-1 to E-5 were used. In detail, the measurement target was placed in a sample chamber of a Raman spectrum spectrophotometer ("NRS-7000" manufactured by JASCO Corporation), and measurement of Raman spectrum was started. In the obtained Raman spectrum, there were a D band derived from a diamond structure and a G band derived from a graphite structure. The D band, Raman shift in wavenumber region is 1320 cm ^-1 or more 1360 cm ^-1 or less, the scattering intensity is maximized. The G-band, Raman shift in wavenumber region is 1520 cm ^-1 or more 1560 cm ^-1 or less, the scattering intensity is maximized. The D band and the G band were analyzed using analysis software installed in the above-mentioned Raman spectrum spectrophotometer. The results are shown in Table 1.

[Manufacture of toner]
(Production of Toner T-1)
First, a polyester resin was manufactured. In the presence of titanium dioxide (catalyst), a bisphenol A ethylene oxide adduct (specifically, an alcohol having a bisphenol A as a skeleton and an ethylene oxide added thereto) was reacted with paraphthalic acid. Thus, a polyester resin was produced. The polyester resin thus obtained had a hydroxyl value (OHV value) of 20 mg KOH / g, an acid value (AV value) of 40 mg KOH / g, a Tm of 100 ° C., and a Tg of 48 ° C.

Next, toner mother particles were produced using the obtained polyester resin. Specifically, 100 parts by mass of a polyester resin, 5.00 parts by mass of a colorant ("KET Blue 111" manufactured by DIC Corporation, phthalocyanine blue), and 5.00 parts by mass of an ester wax (manufactured by NOF Corporation) Nissan Electol (registered trademark) WEP-3 ", melting temperature: 73 ° C), and mixing at a rotational speed of 2400 rpm using an FM mixer (" FM-10C / I "manufactured by Japan Coke Industry Co., Ltd., volume: 10 L) did. The obtained mixture was subjected to a material supply rate of 5 kg / hour, a shaft rotational speed of 160 rpm, a set temperature range (cylinder temperature range) of 80 ° C. to 130 ° C. using a twin screw extruder (“PCM-30” manufactured by Ikegai Co., Ltd.) It melt-kneaded on condition of the following. The obtained melt-kneaded product was cooled. The cooled melt-kneaded product was pulverized using a mechanical pulverizer ("Turbomill T250" manufactured by Freund Turbo Co., Ltd.) to an average particle size of 5.6 μm. The obtained pulverized material was classified using a classifier ("Elbow jet EJ-LABO type" manufactured by Nittetsu Mining Co., Ltd.). As a result, toner base particles having a volume median diameter (D ₅₀ ) of 6.8 μm were obtained.

  The obtained toner base particles had a circularity (shape index) of 0.931, a Tm of 98 ° C., and a Tg of 50 ° C. The triboelectric charge amount of the obtained toner mother particles and the standard carrier N-01 (the standard carrier for negatively charged polar toners provided by the Japan Imaging Association) was −20 μC / g. The zeta potential of the toner base particles in the dispersion adjusted to pH 4 was measured with a zeta potential / particle size distribution measuring apparatus (“Delsa Nano HC” manufactured by Beckman Coulter, Inc.). The zeta potential of the toner base particles at pH 4 is It was -20 mV. From the data of the triboelectric charge and the zeta potential, it was clear that the toner base particles have an anionic property.

  Subsequently, the toner base particles obtained were subjected to an external additive treatment. Specifically, 100 parts by mass of toner base particles and 1.00 parts by mass of DLC / silica particles E-1 are mixed with an FM mixer ("FM-10B" manufactured by Japan Coke Industry Co., Ltd., volume: 5 L). Mix for 5 minutes. In the obtained mixture, the surface of 0.400 parts by mass of silica particles (silica particles having a number average primary particle diameter of 20 nm ("AEROSIL (registered trademark) 90G" manufactured by Nippon Aerosil Co., Ltd.)) was treated with silicone oil and aminosilane Charged silica particles were added and mixed for another minute. Thus, external additives (DLC / silica particles E-1 and silica particles) were attached to the surface of the toner base particles. Thereafter, the obtained toner was sieved using a 300 mesh (48 μm mesh) sieve. As a result, a toner (toner T-1) containing a large number of toner particles was obtained.

(Production of Toner T-2)
Toner T-2 was manufactured according to the method of manufacturing toner T-1, except that DLC / silica particle E-2 was used instead of DLC / silica particle E-1.

(Production of Toner T-3)
Toner T-3 was manufactured according to the method of manufacturing toner T-1, except that DLC / silica particle E-3 was used instead of DLC / silica particle E-1.

(Production of Toner T-4)
Toner T-4 was manufactured according to the method of manufacturing toner T-1, except that the content of DLC / silica particles E-1 was changed to 3.00 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-5)
Toner T-5 was manufactured according to the method of manufacturing toner T-2, except that the content of DLC / silica particles E-2 was 3.00 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-6)
Toner T-6 was manufactured according to the method of manufacturing toner T-3 except that the content of DLC / silica particles E-3 was 3.00 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-7)
Toner T-7 was manufactured according to the method of manufacturing toner T-1, except that the content of DLC / silica particles E-1 was changed to 0.900 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-8)
Toner T-8 was manufactured according to the method of manufacturing toner T-1, except that the content of DLC / silica particles E-1 was changed to 3.10 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-9)
Toner T-9 was manufactured according to the method of manufacturing toner T-2, except that the content of DLC / silica particles E-2 was 0.900 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-10)
Toner T-10 was manufactured according to the method of manufacturing toner T-2, except that the content of DLC / silica particles E-2 was 3.10 parts by mass with respect to 100 parts by mass of toner base particles.

(Production of Toner T-11)
Toner T-11 was manufactured according to the method of manufacturing toner T-4 except that DLC / silica particle E-4 was used instead of DLC / silica particle E-1.

(Production of Toner T-12)
Toner T-12 was manufactured according to the method of manufacturing toner T-4 except that DLC / silica particle E-5 was used instead of DLC / silica particle E-1.

[Evaluation method]
The following evaluation was performed on each of the manufactured toners T-1 to T-12. As an evaluation target, a two-component developer including each of the toners T-1 to T-12 was used. Below, after demonstrating the manufacturing method of evaluation object, an evaluation method is demonstrated.

(Manufactured for evaluation)
First, a carrier was manufactured. Specifically, each raw material is appropriately blended so that 39.7 mol% in MnO conversion, 9.9 mol% in MgO conversion, 49.6 mol% in Fe ₂ O ₃ conversion, and 0.8 mol% in SrO conversion. Water was added and ground and mixed in a wet ball mill for 10 hours. Subsequently, the resulting mixture was dried and held at 950 ° C. for 4 hours.

Subsequently, the mixture was ground in a wet ball mill for 24 hours to prepare a slurry. Subsequently, the slurry was granulated and dried, and held at 1270 ° C. for 6 hours in an atmosphere with an oxygen concentration of 2%, and then the granulated material was crushed. Thereafter, by adjusting the particle size, manganese ferrite particles (carrier core) were obtained. The obtained manganese-based ferrite particles had a saturation magnetization of 70 Am ² / kg at an applied magnetic field of 3000 (10 ³ / 4π · A / m) and an average particle size of 35 μm.

  Subsequently, a polyamideimide resin (copolymer of trimellitic anhydride and 4,4'-diaminodiphenylmethane) was diluted with methyl ethyl ketone to prepare a resin solution. Subsequently, tetrafluoroethylene-hexafluoropropylene copolymer (FEP, fluorocarbon resin) and silicon oxide (2% by mass of the total amount of resin) are dispersed in a resin solution to give 150 g in terms of solid content. An amount of carrier coating solution was obtained. The mass ratio of the polyamideimide resin to the FEP (polyamideimide resin: FEP) was 2: 8, and the solid content ratio of the resin solution was 10% by mass.

  Subsequently, 10 kg of the above-mentioned manganese-based ferrite particles (carrier core) were coated with a fluid-bed coating device ("Spiracoater SP-25" manufactured by Okada Seiko Co., Ltd.) using the obtained carrier coating solution. Thereafter, the resin was coated and the manganese ferrite particles were fired at 220 ° C. for 1 hour. As a result, a resin-coated ferrite carrier having a resin coating amount of 3% by mass was obtained.

  The obtained carrier and each of the toners T-1 to T-12 were mixed to prepare a two-component developer. The content of each of the carrier and the toner was adjusted so that the toner concentration in the two-component developer was 10% by mass. In this way, an evaluation target was obtained.

(Measurement of image density)
First, an evaluation device was prepared. The evaluation target (two-component developer) is placed in the housing portion of the developing device of the color multifunction device ("TASKalfa 5500ci" manufactured by KYOCERA Document Solutions Inc.), and toners T-1 to T-12 are placed in the toner container of the color multifunction device. Put each of them.

  Next, a sample image with a printing rate of 5% was continuously printed on 2000 sheets of printing paper using the prepared evaluation device under the environment of temperature 32.5 ° C. and humidity 85% RH. Thereafter, an evaluation sample image (printing rate: 5%) was printed on printing paper, and the image density (ID) was measured using the printed evaluation sample image. Such a series of operations were performed until the number of printed samples of the sample image with a printing rate of 5% reached 200,000. That is, the image density (ID) was measured every time 2000 sheets of a sample image having a printing rate of 5% were continuously printed.

  In the measurement of the image density (ID), using a reflection densitometer ("SpectroEye (registered trademark)" manufactured by X-Rite), the solid part of the printing paper after printing (the solid part of the formed sample image for evaluation) Reflection density (ID: image density) was measured. If any of the measured image density (ID) was 1.30 or more, it was evaluated as good (o). When any of the measured image density (ID) was less than 1.30, it was evaluated as bad (x). The results are shown in Table 2.

(Measurement of fog density)
The fog density was measured using the evaluation apparatus used for measuring the image density. Specifically, under the environment of temperature 32.5 ° C. and humidity 85% RH, a sample image with a printing rate of 5% was continuously printed on 2000 sheets of printing paper using the evaluation device. Thereafter, a white printing sheet was output from the color multifunction peripheral without printing the sample image, and the fog density (FD) was measured using the output white printing sheet. Such a series of operations were performed until the number of printed samples of the sample image with a printing rate of 5% reached 200,000. That is, the fog density (FD) was measured every time 2000 sheets of a sample image having a printing rate of 5% were continuously printed.

In the measurement of the fog density (FD), the reflection density of the output white printing paper was measured using a color reflection densitometer ("R710" manufactured by Ihara Denshi Kogyo Co., Ltd.). Then, fog density (FD) was calculated based on the following equation.
FD = (reflection density of output white printing paper) − (reflection density of unprinted paper)

  If any of the calculated fog density (FD) was less than 0.003, it was evaluated as good (o). When any of the calculated fog density (FD) was 0.003 or more, it was evaluated as bad (x). The results are shown in Table 2.

(Evaluation of presence or absence of black dot image)
The presence or absence of a black point image was evaluated using the evaluation apparatus used for the measurement of image density. Specifically, a sample image with a printing rate of 5% was continuously printed on printing paper at 200,000 sheets in an environment of a temperature of 32.5 ° C. and a humidity of 85% RH using an evaluation device. Thereafter, a white printing sheet was output from the color multifunction peripheral without printing the sample image, and the output white printing sheet was visually confirmed. Then, it was observed whether or not the black dot image was formed at an interval substantially equal to the diameter of the photosensitive drum on the output white printing paper. When the number of black dot images was 0, it was evaluated as good (o), and when the number of black dot images was 1 or more, it was evaluated as bad (x). The results are shown in Table 2.

(Evaluation of low temperature fixability)
First, an evaluation device was prepared. In order to adjust the fixing temperature (specifically, the surface temperature of the fixing roller), a color multifunction machine ("TASKalfa 5500ci" manufactured by KYOCERA Document Solutions Inc.) was modified. The modified evaluation device was equipped with a heating roller as a fixing roller. The surface layer of the heating roller was made of PFA (copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) and had a thickness of 30 μm ± 10 μm. The surface of the surface layer of the heating roller had a surface roughness of 5 μm in arithmetic average roughness Ra. Then, the evaluation target (two-component developer) was put in the housing portion of the developing device of the remodeled color multifunction machine, and each of the toners T-1 to T-12 was put in the toner container of the remodeled color copier .

Next, in the prepared evaluation device, the linear velocity was set to 300 mm / sec, and the toner loading amount was set to 0.6 mg / cm ² . A sample image (unfixed image) was formed on 60 sheets of printing paper (A4 size) under an environment of temperature 25 ° C. and humidity 50% RH. The formed sample image was fixed on the printing paper by raising the fixing temperature in a temperature range of 80 ° C. or more and 120 ° C. or less by 10 ° C .. Therefore, five types of printing paper on which the sample image was fixed were obtained.

  Subsequently, a rubbing test was performed. Specifically, the printing paper on which the sample image is fixed is folded in half so that the side on which the sample image is formed is inside. Using a 1 kg weight coated with fabric, it was rubbed back and forth 5 times over the crease of the printing paper. Thereafter, the printing paper was spread, and the peeling length (hereinafter, referred to as peeling width) of the toner peeling at the portion where the sample image was formed in the bent portion of the printing paper was measured. When the peeling width was 1.0 mm or less, it was judged as pass. Then, the lowest temperature among the fixing temperatures at the time of formation of the sample image determined to be a pass is defined as the lowest fixing temperature. When the lowest fixing temperature was 100 ° C. or less, it was evaluated as ((good), and when the lowest fixing temperature was higher than 100 ° C., it was evaluated as x (poor). The results are shown in Table 2.

(Evaluation of high temperature offset resistance)
The high temperature offset resistance was evaluated using the evaluation apparatus used in the evaluation of low temperature fixability. Specifically, in the evaluation apparatus, the linear velocity was set to 300 mm / sec, and the toner loading amount was set to 0.6 mg / cm ² . A sample image (unfixed image) having a width of 5 cm was formed on the tip of high-quality paper ("C2 paper" manufactured by Fuji Xerox Co., Ltd., basis weight: 70 g / m ² ). The formed sample image was fixed on wood free paper at a fixing temperature of 180 ° C. In this way, 100 high quality papers on which sample images were printed were obtained. Thereafter, the fixing roller was taken out from the evaluation device, and the presence or absence of high quality paper wrapped around the fixing roller was visually confirmed.

  The sample image (unfixed image) was fixed on wood free paper according to the method described above except that the fixing temperature was changed to 190 ° C., 200 ° C., 210 ° C. and 220 ° C. Thereafter, the fixing roller was taken out from the evaluation device, and the presence or absence of high quality paper wrapped around the fixing roller was visually confirmed.

  If no winding of high quality paper on the fixing roller is confirmed, it is judged as pass, and the highest fixing temperature among the fixing temperatures when it is judged as pass is taken as the maximum fixing temperature. Then, it was evaluated as good (○) if the maximum fixing temperature was 200 ° C. or more, and was evaluated as bad (×) if the maximum fixing temperature was less than 200 ° C. The results are shown in Table 2.

  In Table 2, "content" means the content of DLC / silica particles relative to 100 parts by mass of toner base particles. In the lower part of the column "image density", the measured values of the image density are described. In the lower part of the column "fog density", the calculated value of the fog density is described. In the column "black dot", the evaluation result of the presence or absence of the black dot image is described, and in the lower part of the column "black dot", the measurement value of the black dot image is described. In the lower part of the column "Low temperature fixability", the minimum fixing temperature is described. The column "Offset" describes the evaluation results of the high temperature offset resistance, and the lower part of the column "Offset" describes the maximum fixing temperature.

  The toners T-1 to T-6 (toners according to Examples 1 to 6) each had the basic configuration described above. Specifically, each of the toners T-1 to T-6 contained a plurality of toner particles. The toner particles were provided with toner base particles and an external additive attached to the surface of the toner base particles. The external additive contained a plurality of first external additive particles containing DLC. The content of the first external additive particles in the toner particles is 1.00 parts by mass to 3.00 parts by mass with respect to 100 parts by mass of the toner base particles.

  As shown in Table 2, in the toners T-1 to T-6, the image density, the low temperature fixability, and the high temperature offset resistance were excellent, and the fogging density was low. Also, no black dot image was confirmed.

  The toner T-7 (the toner according to Comparative Example 1) was inferior to the toners T-1 to T-6 in the evaluation of the presence or absence of the black dot image, the evaluation of the low temperature fixability, and the evaluation of the high temperature offset resistance. . The reason why such a result is obtained is considered to be that the content of DLC / silica particles with respect to 100 parts by mass of toner base particles is 0.900 parts by mass.

  The toners T-8 and T-10 (the toners according to Comparative Examples 2 and 4) were inferior in the evaluation of the fogging density as compared with the toners T-1 to T-6, respectively. The reason why such a result was obtained is considered to be that the content of DLC / silica particles with respect to 100 parts by mass of toner base particles was 3.10 parts by mass.

  Unlike the toners T-1 to T-6, the toner T-9 (the toner according to Comparative Example 3) was inferior in the evaluation of the presence or absence of the black dot image. The reason why such a result is obtained is considered to be that the content of DLC / silica particles with respect to 100 parts by mass of toner base particles is 0.900 parts by mass.

  The toner T-11 (the toner according to Comparative Example 5) was inferior to the toners T-1 to T-6 in all evaluations except for the evaluation of low-temperature fixability. The reason why such a result is obtained is considered to be that the number average primary particle diameter of the DLC / silica particles is less than 50 nm.

  The toner T-12 (the toner according to Comparative Example 6) was inferior in all evaluations as compared with the toners T-1 to T-6. The reason why such a result is obtained is considered to be that the number average primary particle diameter of the DLC / silica particles is more than 150 nm.

In addition, this inventor has confirmed that each Raman spectrum shape of DLC / silica particle E-1-E-5 has the following 1st-4th characteristics.
First feature: In each of the Raman spectra of DLC / silica particles E-1 to E-5, there were a D band derived from a diamond structure and a G band derived from a graphite structure.
The second feature: the D band, Raman shift in wavenumber region is 1320 cm ^-1 or more 1360 cm ^-1 or less, the scattering intensity is maximized.
A third feature: in G2 band Raman shift in wavenumber region is 1520 cm ^-1 or more 1560 cm ^-1 or less, the scattering intensity is maximized.
Fourth feature: The full width at half maximum of D band was larger than the full width at half maximum of G band.

  The electrostatic latent image developing toner according to the present invention can be used, for example, to form an image in a copying machine, a printer, or a multifunction machine.

10 toner particle 20 toner base particle 30 first external additive particle 31 first core particle 33 first coat layer 40 second external additive particle

Claims (5)

A toner for developing an electrostatic latent image comprising a plurality of toner particles, wherein
The toner particles include toner base particles and an external additive attached to the surface of the toner base particles.
The external additive includes a plurality of first external additive particles containing diamond-like carbon,
The content of the first external additive particles in the toner particles is 1.00 to 3.00 parts by mass with respect to 100 parts by mass of the toner base particles.
The electrostatic latent image developing toner, wherein the number average primary particle diameter of the first external additive particles is 50 nm or more and 150 nm or less. In the Raman spectrum of the first external additive particle, a first band derived from a diamond structure and a second band derived from a graphite structure are present,
In the first band, the frequency domain is Raman shift 1320 cm ^-1 or 1360 cm ^-1 or less, scattering intensity is maximized,
In the second band, in the frequency domain is Raman shift 1520 cm ^-1 or 1560 cm ^-1 or less, scattering intensity is maximized,
The electrostatic latent image developing toner according to claim 1, wherein a full width at half maximum value of the first band is larger than a full width at half maximum value of the second band. The first external additive particle includes a first core particle and a first coat layer formed on the surface of the first core particle,
The toner for developing an electrostatic latent image according to claim 1, wherein the first coat layer contains the diamond like carbon.   The toner according to claim 3, wherein the first core particle is a silica particle.   The external additive according to any one of claims 1 to 4, wherein the external additive contains a plurality of second external additive particles which do not contain diamond-like carbon but contain silica, and does not contain external additive particles which contain titanium oxide. The toner for electrostatic latent image development as described in a term.